It's hard to blame others when you've already pleaded guilty and been sentenced to prison. But Garth Peterson gave it a try in an interview Friday with CNBC.

Peterson was Morgan Stanley's former managing director for real estate in China. Last week he was sentenced to nine months in federal prison after pleading guilty to conspiring to evade internal accounting controls that Morgan Stanley was required to maintain under the FCPA.

He faced up to five years in prison, and the DOJ had asked for about four years.

(Peterson may have gone on the offensive because the DOJ pushed for a long sentence even after he pleaded guilty to a criminal charge and settled civil charges with the SEC.)

The DOJ and SEC declined to charge Morgan Stanley. They said the firm's compliance program 'provided reasonable assurances' that Morgan Stanley's employees were not bribing government officials. Peterson, they said, was a 'rogue employee.'

In the interview, Peterson said Morgan Stanley's compliance program was less in evidence than the DOJ has claimed.